9mo bedtime screaming

[JimmyJam2019]

For the last few weeks, bedtime has just been about screaming.
Daytime routine is 1.5hrs nap at 9.30am then 1hr at 2pm, can put DD down wide awake and will settle fine.
Normally bedtime is bath, dressed, feed, cuddles and lullabies then white noise on and put down drowsy but awake all fine.
Last few weeks, screaming from the moment she is out the bath.
She needs to be held and rocked until she is asleep and then for a good 5/10 minutes to be sure.
No patting to sleep, gradual retreat....she just screams unless she is picked up and if left can scream for over 30 mins before I break and go into her.
I've tried various bedtimes between 6 and 7 (we go for a 7-7 day) for a few days at a time to be consistent but makes no difference. No teething or illness signs.
Will also wake up and need resettling at least once a couple of hours later but then sleep through until morning.
Help!

Was this change all of a sudden, or gradual?

In the space of two weeks to go from 'put down awake, leave, self settles without crying' to needing to be rocked to sleep fully is a very significant change. I'm assuming she's been easy (ish) to put down for many months before this too? So it's a sudden and very significant change.

She had chicken pox after Easter and then some teething which was all tricky but seemed to be ok for a week or two before we went into this phase.
It's bizarre how naps are so easy to put her down but bedtime is so screamy. We've been lucky up to now, there may be some protest moaning at bedtime previously, lasting all of a minute max, but this is all new.

It's bizarre how naps are so easy to put her down but bedtime is so screamy.

She could be over tired by bedtime?

Would she resettle to lengthen the afternoon nap? You could also try restricting the length of the morning nap to 45 minutes with the hope to lengthen second nap. This isn't always straight forward though because you'll have an interim period where baby is a lot more over tired then she is now.